Bulk Polymerisation or Copolymerisation in a Novel Continuous Kneader Reactor

A new type of kneader reactor is proposed for the continuous radical (co‐) polymerisation without solvent, based on the proven design of mature (kneader‐) dryer technology. The reactor has been developed to satisfy all major aspects required for (co‐) polymerisation while maintaining the safety and reliability of the previous mechanical design. The new kneader reactor offers a perfect combination of surface renewal and evaporative cooling to control temperature to high conversion (85 to 95%), even for bulk systems that have a strong gel effect (Trommsdorff's effect) and high exothermicity. The reactor can be tested batch‐wise to optimise the recipe, as shown in this work for bulk free radical polymerisation of methyl methacrylate (MMA). A simulation program was correlated to the experimental batch data to determine the optimum concentrations of initiator and of chain transfer agent to target a given molecular weight of PMMA. Design of a continuous kneader reactor to optimise the conversion as a function of residence time, to eliminate foam formation, and to produce copolymers without composition drift, is also presented.